### AST_TRANN

Transform N-dimensional coordinates

#### Description:

This routine applies a Mapping to transform the coordinates of a set of points in an arbitrary number of dimensions. It is the appropriate routine to use if the coordinates are not purely 1- or 2-dimensional and are stored in a single array (which they need not fill completely).

#### Invocation

CALL AST_TRANN( THIS, NPOINT, NCOORD_IN, INDIM, IN, FORWARD, NCOORD_OUT, OUTDIM, OUT, STATUS )

#### Arguments

##### THIS = INTEGER (Given)
Pointer to the Mapping to be applied.
##### NPOINT = INTEGER (Given)
The number of points to be transformed.
##### NCOORD_IN = INTEGER (Given)
The number of coordinates being supplied for each input point (i.e. the number of dimensions of the space in which the input points reside).
##### INDIM = INTEGER (Given)
The number of elements along the first dimension of the IN array (which contains the input coordinates). This value is required so that the coordinate values can be correctly located if they do not entirely fill this array. The value given should not be less than NPOINT.
##### IN( INDIM, NCOORD_IN ) = DOUBLE PRECISION (Given)
An array containing the coordinates of the input (untransformed) points. These should be stored such that the value of coordinate number COORD for input point number POINT is found in element IN(POINT,COORD).
##### FORWARD = LOGICAL (Given)
A .TRUE. value indicates that the Mapping’ s forward coordinate transformation is to be applied, while a .FALSE. value indicates that the inverse transformation should be used.
##### NCOORD_OUT = INTEGER (Given)
The number of coordinates being generated by the Mapping for each output point (i.e. the number of dimensions of the space in which the output points reside). This need not be the same as NCOORD_IN.
##### OUTDIM = INTEGER (Given)
The number of elements along the first dimension of the OUT array (which will contain the output coordinates). This value is required so that the coordinate values can be correctly located if they will not entirely fill this array. The value given should not be less than NPOINT.
##### OUT( OUTDIM, NCOORD_OUT ) = DOUBLE PRECISION (Returned)
An array into which the coordinates of the output (transformed) points will be written. These will be stored such that the value of coordinate number COORD for output point number POINT will be found in element OUT(POINT,COORD).
##### STATUS = INTEGER (Given and Returned)
The global status.

#### Notes:

• If the forward coordinate transformation is being applied, the Mapping supplied must have the value of NCOORD_IN for its Nin attribute and the value of NCOORD_OUT for its Nout attribute. If the inverse transformation is being applied, these values should be reversed.

#### Handling of Huge Pixel Arrays

If the number of points to be transformed exceeds the largest value that can be represented by a 4-byte integer, then the alternative " 8-byte" interface for this function should be used. This alternative interface uses 8 byte integer arguments (instead of 4-byte). Specifically, the arguments NPOINT, INDIM and OUTDIM are changed from type INTEGER to type INTEGER$\ast$8. The function name is changed by appending the digit " 8" to the name. Thus, AST_TRANN becomes AST_TRANN8.